CVE-2019-20372

Exp

NGINX before 1.17.7, with certain error_page configurations, allows HTTP request smuggling, as demonstrated by the ability of an attacker to read unauthorized web pages in environments where NGINX is being fronted by a load balancer.

Published: 2020-01-09 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2019-20372 is rated High Exploit Risk (64.9/100): CVSS Medium severity, with high exploitation likelihood (EPSS 14.96%, 96th percentile). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2019-20372

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2019-20372

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 69.57% 14.96% -54.61%
2 2026-05-26 69.32% 69.57% +0.25%
3 2026-05-24 — 69.32% —

Full EPSS history (62 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2019-20372

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2019-20372

OS Trackers for CVE-2019-20372

vendor priority summary link
alpine medium CVE-2019-20372: 1 source package rows (nginx); 26 state rows across 10 repos (3.10-main, 3.11-main, 3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 11, open 15. https://security.alpinelinux.org/vuln/CVE-2019-20372
debian low CVE-2019-20372 low priority: Debian including 1 source packages (nginx), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2019-20372
redhat medium — https://access.redhat.com/security/cve/CVE-2019-20372
suse medium CVE-2019-20372 severity moderate: SUSE including 29 source package names (nginx, nginx-1.14.2-6.7.1, …), 32 product×package rows across 13 product lines (SUSE Liberty Linux 8, SUSE Linux Enterprise High Performance Computing 15-ESPOS, … (13 product lines)): Fixed 30, Known Not Affected 2. https://www.suse.com/security/cve/CVE-2019-20372/
ubuntu medium CVE-2019-20372 medium priority: Ubuntu including 1 source packages (nginx), 6 status rows across 6 suites (bionic, disco, eoan, trusty, upstream, xenial): released 6. https://ubuntu.com/security/CVE-2019-20372

Affected software / configurations for CVE-2019-20372

Vendor Product Version Raw CPE
f5 nginx < 1.17.7 cpe:2.3:a:f5:nginx:*:*:*:*:*:*:*:*
apple xcode < 13.0 cpe:2.3:a:apple:xcode:*:*:*:*:*:*:*:*
canonical ubuntu_linux 14.04 cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:esm:*:*:*
opensuse leap 15.1 cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*
netapp cloud_backup — cpe:2.3:a:netapp:cloud_backup:-:*:*:*:*:*:*:*

References for CVE-2019-20372

URL Tags
http://lists.opensuse.org/opensuse-security-announce/2020-02/msg00013.html Mailing List Third Party Advisory
http://nginx.org/en/CHANGES Mitigation Release Notes Vendor Advisory
http://seclists.org/fulldisclosure/2021/Sep/36 Mailing List Third Party Advisory
https://bertjwregeer.keybase.pub/2019-12-10%20-%20error_page%20request%20smuggling.pdf Exploit Mitigation Third Party Advisory
https://duo.com/docs/dng-notes#version-1.5.4-january-2020 Release Notes Third Party Advisory
https://github.com/kubernetes/ingress-nginx/pull/4859 Patch Third Party Advisory
https://github.com/nginx/nginx/commit/c1be55f97211d38b69ac0c2027e6812ab8b1b94e Patch Vendor Advisory
https://security.netapp.com/advisory/ntap-20200127-0003/ Third Party Advisory
https://support.apple.com/kb/HT212818 Third Party Advisory
https://usn.ubuntu.com/4235-1/ Third Party Advisory
https://usn.ubuntu.com/4235-2/ Third Party Advisory
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